Genus: Only 1 emergent flagellum; locomotory flagellum directed anteriorly, straight, during swimming; colourless, phagotrophic; no eyespot; rigid, solitary, ovoid, usually flat, with several keels; freshwater (Illustrated Guide, 1985). Oval or pyriform; not plastic; pellicle often with straight or spiral furrow; a single flagellum; many species (Kudo, 1966).
Species: 30-35 μm; 2 dorsal, 2 ventral grooves on either side of dorsal and ventral keels (How to know the protozoa, 1979).
Similar genus -->> Notosolenus;
P. bicarinata
or P. dorsalis ?
cell 28 x 18 μm
flag. 28 μm
Japan, 1997
P. bicarinata
cell 24 μm
flag. 30 μm
or P. dorsalis ?
Hiroshima, 1998
Movies 
P. bicarinata ?
cell 29 x 17 μm
flag. 29 μm
Ageo Maruyama Park
Saitama, 2002
P. bicarinata ?
cell 30 x 18 μm
flag. 24 μm
Kugedo
Kawagoe
Saitama, 2005
P. bicarinata ?
cell μm
flag. μm
Karakemi m.1
Omachi
Nagano, 2008
